Pusher/generator trailer idea.

[Isaac Zackary]

The last turbine setup I saw basically would empty a 15 gallon tank of kerosene just to park the thing!

[Isaac Zackary]

The last time I saw a gas turbine on a car it basically would empty a 15 gallon tank of kerosene just to park the thing! That was on a VW Bug just like mine!

[Astro]

Originally Posted by Piotrsko

Uh....... most of the batmobiles I've seen (5 out of 12) run either a 352 or 460 with one 429 variant

I was just commenting based on my memory of watching old Batman shows and the cars invariably has some form of jet exhaust out the back complete with afterburner type flames.
I had a look at wikipedia and according to the technical specifications many of the Bat mobiles had one or more jets but they apparently also had ICE engines. The jets were used for fast starts or when extra speed was required.
So the Bat mobile had a jet turbine, it just wasn't it's sole source of locomotion.

[Astro]

Originally Posted by Isaac Zackary

The last time I saw a gas turbine on a car it basically would empty a 15 gallon tank of kerosene just to park the thing! That was on a VW Bug just like mine!

If it was using the thrust to move then i am not surprised. I don't imagine a jet plane gets very good MPG figures taxiing around on the ground either.
If the turbine was the sole source of motive power then it would need to be sized to meet the maximum power that the vehicle may require. It's load would always be changing just like an ICE and so it wouldn't always be operating at it's most efficient speed or load.
When the turbine will be used at a constant rate to extend the vehicles range then the turbine can be sized to match the continuous load. So a 10kW requirement could be met by a turbine which is operating at 100% load at 10kW or whatever is the most efficient match to the load. The range extending turbine would be either operating at it's most efficient speed or it would be switched off.
BTW, i hadn't thought of using a turbine until Isaac's post. It was just one of the first engines that popped up on a search for a high power to weight ratio engine. So not necessarily the most efficient.
And the photo of the micro turbine sitting next to the pencil just looked so cool.

[Isaac Zackary]

VW transaxle with garret turbine engine.

This is what I saw! It's hooked to a 4 speed transmission.

[deejaaa]

you've got some reading to do.
Mr.Sharkey's Pusher Trailer
Is It Vaporware? Tow-along Solution Offers To Volt Your Leaf
EV Weblog: EV Pusher
TheSamba.com :: View topic - Looking for resources/help to "hybridize" a Square

[Astro]

Originally Posted by Isaac Zackary

VW transaxle with garret turbine engine.

This is what I saw! It's hooked to a 4 speed transmission.

That's bit of a beast.

It's about 10 times the capacity of the micro turbine.
At a max of 40,800 RPM it is going to be noisy all over the audible range.
The slow RPM response of a turbine is going to make it interesting when parking.
It would be one of those things that are cool to play around with but not something you would want to use regularly or as your main transport. As the eBay listing suggests, more a dune buggy / sand rail sort of thing. Even then, the noise probably would be quite annoying to both the driver and any spectators after a short time.

I imagine that for the range extending duties on an EV, using the micro turbine would reduce/remove these issues.
The RPM is much higher so shouldn't be too loud (dogs may disagree ).
Small size may allow mounting in the EV rather then requiring a trailer.
Runs at a single speed, it's most efficient RPM. Slow RPM response wouldn't matter.
Of course these are all guesses.
The refinements in the technology are recent enough that there would be few examples to look to. Range extending rather than full hybridising an EV using a micro turbine has probably not been tried. Maybe because it won't work or is impractical or maybe because the technology has been too expensive or unavailable until now.

[Isaac Zackary]

So, I've been brain-storming this a bit lately since I'm seeing it more feasible for me to buy a Leaf. Here's the most practical ideas I can think of:

1. Front clip off of another car with engine and transmission and all, turned into a pusher trailer.
Pros: No need to build a power train from the engine to the wheels. If the car is newer, it can be kept with all the low emissions stuff.
Cons: Throttling difficulties. More power than what is needed. Lot's of cutting and welding and relocating. More weight than what is needed. Can't be left off unless the transmission is manual and can be shifted into neutral

2. A small ~16hp engine. (I'm personnaly thinking about one of the Kohler propane EFI engines with a catalytic converter even though they're rated a bit high, about 21hp, although that's without the air filter and exhaust.) That hooked up to an 18hp go-cart "torque converter" CV transmission. Then the Comet Forward/Reverse/Neutral transmission placed betweent the CV transmission and a go-kart differential on an axle with to two wheels, or even better, a one wheeled trailer with no differential. I'd need to somehow make some form of suspention for it. This could also be made from the rear end of a scooter or motorcycle.
Pros: Much smaller, not so much power. Can be shifted into neutral with the Comet transmission and engine turned off. Still sort of emissions friendly with the EFI propane engine and catalytic converter. Won't have to be seen at a gasoline station with an electric car if propane propelled. Can be much lighter and smaller.
Cons: Throttling is still a challenge.

3. A small engine and a 12kW BLDC motor, rewound to produce 400V and up to 30A by 5000RPM, fed in to a rectifier (basically turning it into a large alternator) and hacking into the main Nissan Battery cable. An alternative would be to run a large generator and get a 400V charger.
Pros: Can be turned on and off at will. Can charge the battery even when stopped. Also could be propane powered.
Cons: I could get electricuted or ruin something as expensive as the battery itself. Controlling charge so that it not only doesn't overcharge he battery, but also doesn't over-amp the battery durring regen would be difficult to design.

[Astro]

I wonder how hard it would be to disable the interlock that prevents an electric car moving whilst charging. Then a simple trailer or bike rack style mount for an off the shelf generator plugged into the normal car charge circuit. Easy to attach, a bit of hacking on the interlock but that may be software only. Then you have a useful range extending device made from readily available and replaceable components..
Buy the model that runs on the fuel you want to use, diesel, propane, etc. It would also be able to be used as an emergency power supply for your house. Used to get your car to a camp site and then used to power the camp site.
Take the generator out of the trailer and you have a useful trailer.
Each component would be useful beyond just its use as a range extender.

[Isaac Zackary]

One potential problem I see is that if the generator is charging the car and you hit the brakes and it goes into regen mode it could over-amp the battery. Remember that the car isn't designed to drive and charge at the same time. But an easy solution would be to put a contactor on the charging line that opens whenever your brake lights are activated. And just don't use B mode. That way you'll know that you're not over-amping the charging of the battery.

Another thing would be the wiring. It would look kind of funny having a chord that goes along the top of the Leaf to the charging port in the front. But yes, I agree that a generator system would be useful, even if you had to drop the battery to route the charging wires from the rear. (Then you could park either way at charging stations. )

I think my idea to convert an electric motor into a high voltage 12kW alternator would be cheaper and produce twice the power that you could get from a generator. The charging system in 2013 and later Leafs only supports 6.6kW charging (in 2011 and 2012 models it's half that.) If you get 100 miles out of 50 miles an hour (two hours) then your using about 12kW of juice. A 7kW generator plugged in to the Leafs charging system via a 6.6kW charging cord will give you about double the range, 200 miles, before you have to sit and wait 4 hours for the battery to charge up again. A 12kW system or higher would be closer to being able to drive all day for hundreds and hundreds of miles without having to stop and charge up every so often.

Also you would want to be careful with the generator you chose. Generators tend to be hard on electronics. About the only electronics trustworthy generator that can produce 7kW is the Honda EU7000. Actually, I'm thinking of getting the smaller Honda EU2000 for level 1 charging and keeping it in the Leaf for emergencies.

But on that same note, a motor converted to an alternator would produce a DC voltage that could be more easily smoothed out.